How to view "From" header field in OUTgoing messages in Mail? Frustrating.

Question

In Mail v.4.3 (in OSX 10.6.4), I need to view the "From" field in my outgoing messages as I am composing them. However, there seems to be no setting in Mail which allow this.
I find this very frustrating because in Eudora (which I used to use), the "From" field in outgoing messages is visible by default. But in Mail, not only is it not visible by default, there seems to be no way to make it visible.
In the "Customize..." button to the left of the Subject field in outgoing messages, one has the option to add as default outgoing message fields "cc," "bcc," "Reply-To," and "Subject," but none of those are what I want. It allows one to also view the address of the mail server, but that also is not what I'm looking for. What I want is to see my outgoing +email address+. And nowhere is there an option in the Preferences to turn this on. (At least as far as I could tell.)
In fact, the only way to see the identity in the outgoing "From" field is to go to Preferences, then click on Accounts, and look there; or send oneself a test email. Both of which are a hassle and should be unnecessary.
In case you're curious as to why I want to see my outgoing "From" header field:
I have several different "personas" online, each of which uses a different email address: My work address (with a work-related domain); my family/personal address (with a different email address than my work address); an online avatar I use in various gaming sites (also with its own address, since I don't want to use my personal name/address in the gaming community); and so on. However, I have all incoming emails to all accounts auto-forwarded to the same central email account. Most of the time I'm just replying to business emails, so my outgoing "Full Name" and "Email Address" (in Preferences>Accounts) are generally set to my business name and address; but on occasion when I want to reply to a non-business email and not have the recipient see my business email address, I go in to Preferences>Accounts and change "Full Name" and "Email Address" (i.e. what is displayed to the user) to something different. And when I'm done with that, I change it back to my business address.
However, sometimes I forget if I've changed it back or not, or forget what I've changed it to. In Eudora, All one needed to one was create a new outgoing email and it would display the "From" field so I could instantly see my outgoing identity. But in Mail, there is no "From" field in outgoing emails, so I'm constantly nervous and wondering which outgoing identity I may have changed to and accidentally forgotten to change back from.
(Yes, yes, I know that if a recipient wanted to be snoopy, they could look at the "full headers" of any incoming email and see the name of my email server, which may different from my displayed email address; but we're not talking about spy-stuff here, I'm just trying to not confuse people and keep business separate from personal.)
So: is there any way for me to see the outgoing "From" field in the emails I send? Or am I condemned to constantly (and mostly unnecessarily) checking "Preferences>Accounts" to see what I have enetered there?

Answer 1

Thanks for replying.
What is the "compose window" to which you are both referring? I could find no reference to such a thing in the Mail menus or Help.
Do you mean the "Composing" pane in the Preferences? I don't see what either one of you is referring to there, but I did notice there something that could function as an awkward workaround: If I click on the "Automatically CC myself" box in Preferences>Composing, then when I start a new email, my email address is displayed in the "CC" field -- and luckily, Mail allows me to then delete my email address out of the CC field, so I don't have to spam myself with duplicate copies of all my emails. This way, I can at least briefly see what email address I'm using, before I delete it from the CC field. Pretty awkward and unnecessarily laborious, however -- still not a perfect solution.
Or, by "composing window," are you referring to an outgoing email? As I said in my original comment, I do see what Ernie called "a small box with lines and an arrow at the bottom left of the header box." This is what I had to say about it:
+"In the "Customize..." button to the left of the Subject field in outgoing messages, one has the option to add as default outgoing message fields "cc," "bcc," "Reply-To," and "Subject," but none of those are what I want. It allows one to also view the address of the mail server, but that also is not what I'm looking for. What I want is to see my outgoing email address. And nowhere is there an option in the Preferences to turn this on. (At least as far as I could tell.)"+
In other words, when Ernie says, "click the box beside From," I can't do that -- because there is no such option. That's the whole problem in the first place. If there was a "From" field beside which I could click a box to make it appear, I would have done so! But there is no "From" field in the "Customize" section of the "small box with lines and an arrow at the bottom left of the header box."
I find it completely mystifying that both of you seem to be able to see a "From" field available to be added to the header of outgoing emails, yet no such option is available to me in Mail. What possibly could be causing this? 10.6.4 is freshly installed on my machine, and Mail seems brand new and uncorrupted. And I'm using Mail 4.3, the latest version.
Are you saying that everyone else can see an option to have a "From" field in their outgoing messages, but I uniquely don't? Very very very strange.